Pump



Jan. 13, 1959 E. K. BENEDEK PUMP F'il ed May 13, 1954 w m L new 5 (e12K. fie/zeoek, deceased Mel L. ezzedek, (2092? '12::

M! i Z [7775 United States PUMP Application May 13, 1954, Serial No.429,632

1 Claim. (Cl. 103-161) The present invention relates to pumpconstruction and, more particularly, relates to radial piston type pumpsconstructed to provide a substantially constant outlet pressure andcapable of simple modification to vary its capacity.

,The basic principle of operation of the radial type pump has, ofcourse, long been understood in the art. I am of course aware of priorart pump structures wherein a drive member is rotatably mounted on afixed pintle and carries a plurality of radially extending bores inwhich reciprocatable pistons are mounted. I am also, of course, aware ofthe fact that numerous means and methods of reciprocating the pistonshave been provided in the prior art, among which is the expedient ofpositively actuating the pistons by means of a circular cam mountedeccentrically of the axis of rotation of the drive member. The presentinvention is an improvement over these prior art devices and provides agreat simplification and hence reduction in expense over those pumpsheretofore known.

In the pump construction of the present invention, a single conventionalball or roller bearing having an inner and outer race separated byrolling balls or rollers, is provided for actuating the reciprocatingpistons, and the pistons themselves are constructed of conventionalhardened roller bearings slidable axially along their length as a resultof forces applied against the ends thereof by the inner race of theabove mentioned bearing. By utilizing those conventional parts in anovel manner and in combination with other simplified structuralcomponents, applicant has been able to provide an unusually efi'icientpump capable of manufacture at a minimum of cost.

It is therefor an object of the present invention to provide a novel andimproved radial piston type pump.

Another object of the present invention is to provide a novel pistontype pump wherein the pistons comprise free floating cylindricalmembers.

Still a further object of the present invention is to provide a novelfuel pump or the like having radially movable reciprocal pump pistonsand wherein reciprocation of the pistons is accomplished by thepositioning thereof within the inner race on an anti-friction rollerbearing mounted eccentrically of the pump drive.

A feature of the present invention is the provision of a pump capable ofmanufacture from cylindrical parts almost exclusively.

Another feature of the present invention is a novel piston actuating andcarrying block mounted for rotation on a fixed pintle and positionedwithin the inner race of an anti-friction bearing for the reciprocationof the pistons without positive driving connection therewith.

Still another object of the present invention is to provide a simplifiedradial-type fluid pump for operation at a substantially constant maximumoutput pressure.

Still other features and objects of the present invention will at oncebecome apparent to those skilled in the art from a consideration of theattached drawings wherein:

Figure 1 is a side elevational view in cross-section ilatent O"2,868,136 Patented Jan. 13, 1959 ice ' 2 lustrating the assembly of apump constructed according to the present invention.

Figure 2 is a cross-sectional view taken along the line II-ll of Figurel and illustrating applicants novel piston and piston actuationmechanism, and

Figure 3 is a cross-sectional view taken along the line III-llI ofFigure 1 illustrating applicants simplified outlet pressure control.

As shown on the drawings:

As may be seen from consideration of Figures 1 through 3, the pump ofthe present invention comprises a housing 10 having a pintle supportaperture 11 at one end thereof and having a flange 12 at the oppositeend for the attachment of a closure end plate 13. The end plate 13carries a cylindrical bearing 14for supporting a rotatable drive shaft15.

A conventional non-rotatable cantilever type pintle 16 is rigidlysecured within the aperture 11, preferably by means of a shrink or pressfit. As may be seen from Figures 2 and 3, the pintle is provided with apair of longitudinally extending bores 17 and 18 for conducting fluidfrom the pump inlet 19 to the outlet 20 via the suction and pressurepumping chambers 21 and 22 respectively.

The pumping mechanism of the pump comprises a rotatable cylinder block23 having a bore 24 therein for rotatable cooperation with the pintle16. The block 23 is preferably machined from a cylindrical bar forpurposes of cost minimization and is provided with a generally polygonalaperture 25 at the right hand end thereof for cooperation with a similarpolygonal shaped end 26 on the drive shaft 15.

The cylinder block 23 is provided with a plurality of radially extendingcylinder bores 27 in which reciprocable pistons 28 areslidablyrnount'ed. In the inexpensive pump unit contemplated, it ispreferred that the pistons 28 comprise hardened needle or rollerbearings of a selected conventional size but it will, of course, beunderstood that other materials may be satisfactorily used.

Sliding movement of the pistons 21 is limited by an abutment shoulder27a in the bottom of each cylinder 27. This abutment prevents thepistons 28 from dropping into the slotted chambers 21 and 22 when thepump is not in operation.

The pistons 28 are forced radially inwardly toward the pintle '16 bymeans of the eccentric action of the internal bearing race 29a of theball bearings 29. The external race 2% is fixably secured in the housing10 by means of an annular spacer ring 30 and an abutment shoulder 31.The circular bore in which the outer race 2% sits is, of course,eccentric to the axis of rotation ,of the cylinder block 23 and,depending upon the eccentricity the length of the effective pistonstroke varies. It will be understood that while for sake of simplicitythe pump of the present invention is illustrated with a fixedeccentricity, nevertheless, adjustment may be accomplished if so desiredby mounting the outer race 29b in a block slidable transversely of thepintle 16.

In operation, the cylinder block 23 is rotated by the shaft 15 relativeto the pintle 16. This rotation will cause a centrifugal force to beapplied against the pistons 28 urging them radially outwardly againstthe internal ring 29a of the bearing 29. The outward force will causethe pistons to move outwardly where possible drawing fluid from theinlet 19 and causing a frictional drive between the outer ends of thepistons 28 in the internal bearing race 29a. This frictional contactwill cause the bearing race 29a to rotate with the cylinder block 23since the friction between the bearing races 29a and 29b is very small.As a result of the eccentricity of the ball bearing 29, on one side ofthe pintle 16 the pistonswill be permitted to move outwardly and on theoppositeside thereof, the bearing 29a will force the pistons inwardly topump fiuid from the outlet 20.

Lubrication of the entire device is achieved through the slight leakagepermitted around :the external wall of the pistons 28. This leakage oilfully .lubricates all of the relatively few moving parts and isprevented fromcg'ress of the shaft 15 by means of the seal v32. Sincethe pintle 16 is preferably pressed into .the housing bore 11, there issubstantially ,no leakageat .the bore .11. However, in order to renderleakage absolutely impossible, a safety O-ring 33 is preferablyprovided.

While it has been found that the pump operates extremely satisfactorilyas above described, it is also within the scope of the present inventionto providecompression springs for urging the pistons 28 radiallyoutwardly. Such springs maybe positioned between the piston stopabutment 27a and-the-pistons 28 to provide a substantially positivesuction stroke in .pump applications in which the cylinder block 23 isintended to rotate at a relatively low angular velocity.

From the above description -it will be apparent that applicant :hasprovided a novel and extremely simple radial piston-type pump. Throughthe construction herein shown conventional bearings may be utilized forthe pump piston actuation, as well as for the pump pistons themselves.Further, assembly of the device is exceedingly simple since nomechanical connections are necessary between the various rotating parts.This absence of connections also eliminates any noise which often hasbecome excessive in prior art pumps and which is, of course undesirable.This-is particularly true when pumps of the type herein disclosed are tobe utilized as fuel pumps for .oil furnaces, vehicles and other similartypes of apparatus which must necessarily run in the ,hearing presenceof people.

An extremely simple and yet highly effective pressure limiter isprovided in the pump of the present invention as maybe seen in Figure 3.There, the pintle 16 is. provided with a slight transverse channel '34leading to a radially directed port 35. A check valve in'the form of aball bearing 26 is resiliently urged against the outer end :of the port35 by means of a spring 37. Upon the attainment of the desired pumpoperating pressure, the check valve ball 36 will unseat permitting fluidto flow from the passageway 18 to the passageway 17 through the reliefport 38. In this manner, a very simple pressure relief valve isprovided, capable of manufacture from a single radial bore, therebyeliminating the necessity for a plurality of closure plugs and othersimilar devices ordinarily utilized in connection with pump valvestructures.

It will be apparent, therefor, that I have provided a novel and highlyeflicient pump having an absolute minimum of moving parts and utilizinga maximum of standard parts readily available at mass produced or volumeprices. As will be apparent, the pump of the present invention may bemanufactured with an absolute minimum of tools and, in situations wherethe bearings are readily available, rotary machining equipment such aslathes are practically the only tools necessary for construction of thisdevice.

It will be understood that variations and modifications maybe made tothe above identified structure without departing from the scope of thenovel concepts of the present invention and it is not, therefore,intended that the application be limited except as necessitated by thescope .of the appended claim.

What is claimed is:

A radial piston pump comprising a fixed pintle having inlet and outletports therein, a cylinder block rotatably mounted on said pintle, aplurality of radially extending bores in said block for sequentialcooperation with said inlet and outlet ports, a .cylindrical pistonfreely slidable in each of said bores, a roller bearing positionedaround saidcylinder block with the inner race thereof in abuttingrelation with the outer ends of said pistons, a fixed housing supportingsaid pintle and roller bearing in eccentric relation to each other, aradial passage extending through said housing to a point adjacent saidpintle and having a diameter overlapping extensions of said inlet-andoutlet ports, and separate apertures connecting said passage with therespective inlet and outlet, said aperture connecting said outlet tosaid passage being substantially concentric of the axis of said passageand said aperture connecting said inlet to said passage being eccentricof the axis of said passage and a spring pressed check valve in saidpassage and normally closing the aperture leading to the outlet toprovide a high pressure bypass from said outlet to said inlet saidpassage providing the guide for said valve with the spring of saidspring pressed valve being positioned concentric of the axis of saidpassage and the check valve having its outer surface guided by the wallsof the passage for concentrically contacting and closing the apertureconnecting the passage and the outlet.

References Cited in the file of this patent UNITED STATES PATENTS1,112,158 Pedersen Sept. 29, 1914 2,130,299 Ernst Sept. 13, 19382,292,181 Tucker Aug. 4, 1942 2,293,693 Wylie Aug. 18, 1942 2,646,755Joy July 28, 1953 2,743,582 Wiedmann May 1, 1956 FOREIGN PATENTS 594,852Great Britain Nov. 20, 1947

